用于辐射诊断的多曝光瞬态成像系统关键技术研究

Pulsed radiation field physical diagnosis is an important means of high energy density physics research such as hydrodynamics, laser plasma, Z-pinch, etc. One of the key diagnostic methods is to acquiring dynamic images through high energy ray perspective imaging or through spatial-temporal distribution measurement of the pulsed radiation field itself. These acquired images often represent the target’s changing process and feature. Correspondently, the images are used to verify the designed model of the theory. Fine diagnosis of pulsed radiation field needs a specific radiation imaging method that can record the whole process with very high spatial and temporal resolution at the same time. In some extreme conditions, the feature time of the pulsed radiation field is as short as several nanoseconds and the time of the whole process is shorter than a microsecond. This project proposed a novel imaging and radiation detect method by combining quick response scintillator, nanosecond time response MCP image intensifier, sub-microsecond time precision image sensor, and computation photography all together. An imaging system with nanosecond precision, high special resolution and the ability to acquire several images can be built The research results will found a new method in sub-microsecond time zone of pulsed radiation field or transient phenomena research.

脉冲辐射场物理诊断是流体动力学、激光及Z箍缩等高能密度物理研究的重要手段。通过高能射线透视研究目标成像或对自发脉冲辐射场强度时空分布进行测量，获取目标变化过程和特征规律的动态图像，用于检验理论设计模型等，是脉冲辐射场物理诊断的基本方法之一。精细化的脉冲辐射场诊断需要同时具有高空间分辨和时间分辨。某些极端条件下的脉冲辐射场物理特征时间在纳秒量级、而总持续时间过程仅在百纳妙到亚微秒量级。本项目在研究CMOS图像传感器性能的基础上，结合CMOS超快电子快门技术、多曝光技术和MCP重频曝光技术，致力于建立一种时间分辨率达到数纳秒级、可连续获多幅图像的射线图像瞬态成像系统研制技术和一种大动态ICMOS成像系统研制技术。研究成果将为亚微秒时间历程的脉冲辐射场过程或瞬态物理机理及规律研究提供新颖的技术手段。

针对超高速物理过程精细图像诊断难题，开展了单台多幅图像获取ICMOS成像系统设计技术研究。项目重点研究了CMOS图像传感器超快图像获取技术、CMOS 瞬态性能研究、MCP 像增强器重频性能研究、纳秒级时间精度同步与触发技术、ICMOS动态扩展技术、图像校正与处理等关键技术，建立了单台获取2幅以上图像的ICMOS样机。开展了轻气炮弹丸超高速飞行过程图像诊断实验，单台相机分别拍摄了2幅特定时刻图像和2幅多曝光图像，图像清晰反映了弹丸飞行速度、姿态和弹托分离情况。项目完成了全部研究目标，研制 ICMOS 样机一套，发表学术论文7篇，在投学术论文3篇，申请／授权国家发明专利5项。项目超快双画幅技术已经应用于自研 ICMOS 相机和光电融合分幅相机中，并拟在自然科学基金重大科学仪器项目中继续使用。